Apparatus to align panels in projector

ABSTRACT

Disclosed is an apparatus to align panels in projector including synthesizing system holding means located on an upper portion of a synthesizing system for supporting the synthesizing system. The apparatus to align panels in projector can prevent deviation(misalignment) between at least two or more prisms and panels, which are mounted on the synthesizing system, due to vibration.

TECHNICAL FIELD

[0001] The present invention relates to an apparatus to align panels ina projector, and more particularly, to an apparatus to align panels in aprojector for preventing deterioration of the quality of an imageprojected on a screen by maintaining alignment between the LCD panels tooptical paths through precisely maintaining alignment of prisms andLCD(Liquid Crystal Display) panels.

BACKGROUND ART

[0002] In general, a projector is a device for projecting strong beam oflight on an image embodied in a panel, namely, an LCD(Liquid CrystalDisplay) panel and projecting image signal on an external large-sizedscreen through a projection lens. Hereinafter, an LCD projectorutilizing the LCD panel as a panel will be described.

[0003]FIG. 1. is a perspective view showing a state that an upper casingof a conventional LCD projector has been removed, FIG. 2 illustrates aperspective view of a synthesizing system area of the conventional LCDprojector, and FIG. 3 illustrates an exploded perspective view of FIG.2. As shown in the drawings, the LCD projector includes a casing 11, aprojection lens 13 for projecting beam synthesized at the side of thecasing 11 on a screen (not shown) arranged outside, an illuminatingsystem 21 having a beam source (not shown) provided at an inner side ofthe casing 11 and a plurality of optical lenses, optical filters andreflection mirrors, which are not shown in the drawings, for dividingbeam irradiated from the beam source into tree color beams, that is, redcolor beam, green color beam and blue color beam and forming threeoptical paths, a synthesizing system 31

[0004] Disposed between the illuminating system 21 and the projectionlens 13, synthesizing divided beams and providing to the projection lens13, and a cooling system 61 for cooling the synthesizing system 31.

[0005] An illuminating system casing 22, which divides beam irradiatedfrom the beam source mounted therein into three color beams of red,green and blue and forms three paths for each beam, is disposed on acircumference area of the synthesizing system 31.

[0006] Moreover, the synthesizing system 31 includes a plurality ofdichroic prisms 35 mounted in predetermined intervals and parallel toeach other, on a plurality of LCD panels 33, and a prism holder 37 forsupporting the dichroic prisms 35.

[0007] The prism holder 37 includes a holder body 39 having a horizontalpart 41 arranged parallel to a bottom surface of a casing 11 and avertical member 45 vertically placed on the side of the horizontal part41 has a center passage in which the projection lens 13 insertedthrough, and top and bottom plates 49 and 51 respectively are placed atthe top and bottom of each prism 35 to provide support for the prisms35.

[0008] Furthermore, the prisms 35 are provided on three sides other thanthe side in which a projection lens is connected, and arranged in aright angle to each other, and an upper plate 49 is connected to anupper part of the prisms 35 for fastening the prisms on relativepositions to one another. Additionally, the top plate 49 has a pluralityof screw holes 50 for fastening a fixed board 34 supporting the LCDpanels 33 with fixing screws 42.

[0009] The vertical member 45 of the holder body 39 has a plurality ofscrew holes 47 at both sides thereof for connecting the illuminatingsystem casing 22. The screw holes 47 are separated to each other along avertical direction. The horizontal part 41 has a seating portion (notshown) for seating the bottom plate 51, on which the prisms 35 areconnected. The seating portion has LCD panel connecting holes 43 in acircumferential area thereof for arranging the LCD panels 33, parallelto each other, on an outer side of each prism 35.

[0010] Meanwhile, if light projected from the beam source is divided bythe illuminating system 21 and passes the corresponding LCD panels 33,each LCD panel 33 is increased in temperature due to increase of heatflux. Furthermore, generally, if the temperature of the LCD panel 33 isincreased by more than a prescribed temperature, namely, criticaltemperature, elements are damaged. Therefore, as a cooling means (notshown) is provided for cooling the synthesizing system through inducingthe outside air in an adjacent area (especially, an upper portion) ofthe synthesizing system or for discharging the inside air to theoutside.

[0011] However, because such conventional LCD projector is deviated froman original position, for example, that the prisms 35 and/or the LCDpanels are distorted relatively to the optical paths of the projectionlens 13, due to vibration of the cooling fan, pixel positions of threecolor beams projected to the LCD panels and formed on the screen aredifferent from each other, thereby deteriorating quality of image.

[0012] Meanwhile, in case of a ceiling hanging type LCD projectorinstalled on the ceiling by dislocating upper and lower portion of theprojector, as time passes due to repeated action of vibration by thegravity and the cooling fan, the fixed board 34 supporting the LCD panel33 at the upper portion is deteriorated in quality of image due tomisalignment by deviation of alignment between the LCD panels 33 and/orthe prisms 35 to the optical paths.

DISCLOSURE OF INVENTION

[0013] Accordingly, the present invention is directed to a warm standbyduplex device and a method for operating the same that substantiallyobviates one or more problems due to limitations and disadvantages ofthe related art.

[0014] It is an object of the present invention to provide an apparatusto align panels in projector, which can prevent deterioration of qualityof image due to deviation of alignment between LCD(Liquid CrystalDisplay) panels and/or prisms to optical paths, that is, change ofrelative position due to misalignment.

[0015] Additional advantages, objects, and features of the inventionwill be set forth in part in the description which follows and in partwill become apparent to those having ordinary skill in the art uponexamination of the following or may be learned from practice of theinvention. The objectives and other advantages of the invention may berealized and attained by the structure particularly pointed out in thewritten description and claims hereof as well as the appended drawings.

[0016] To achieve the above object, the present invention provides anapparatus to align panels in projector including: a synthesizing systemhaving prisms formed at a rear portion of a projection lens forsynthesizing beam, panels mounted parallel to the prisms for formingimage and a prism holder having an upper plate located on the upperportion of the prisms for supporting the prisms and the panels; anilluminating system casing having a receiving space opened toward aprojection lens side for putting the synthesizing system on the casingand optical paths for irradiating different beams on the panels; and asynthesizing system holding plate for holding the synthesizing system atan upper portion, the synthesizing system holding plate having both endslocated on the illuminating system casing and at least one portionlocated on the upper plate.

[0017] As preventing the misalignment between the prisms and the LCDpanels due to vibration by supporting the prisms and the LCD panels atboth ends along a vertical direction, the apparatus to align panels inprojector according to the present invention can continuously maintainan image quality condition in an initial alignment state by preventingdeterioration of quality of image. Additionally, a ceiling hanging typeprojector can effectively prevent misalignment of the LCD panels and theprisms due to gravity.

[0018] It is to be understood that both the foregoing generaldescription and the following detailed description of the presentinvention are exemplary and explanatory and are intended to providefurther explanation of the invention as claimed.

BRIEF DESCRIPTION OF DRAWINGS

[0019] The accompanying drawings, which are included to provide afurther understanding of the invention and are incorporated in andconstitute a part of this application, illustrate embodiment(s) of theinvention and together with the description serve to explain theprinciple of the invention. In the drawings:

[0020]FIG. 1 is a perspective view showing a state that an upper casingof a conventional LCD(Liquid Crystal Display) projector is removed;

[0021]FIG. 2 is a perspective view of a synthesizing system area of theconventional LCD projector;

[0022]FIG. 3 is an exploded perspective view of FIG. 2;

[0023]FIG. 4 is a perspective view showing a state that an upper casingof a LCD projector according to the present invention is removed;

[0024]FIG. 4 is a flowchart of the duplex control signals according tothe present invention;

[0025]FIG. 5 is an exploded perspective view, partially enlarged;

[0026]FIG. 6 is an enlarged plan view of a supporting plate area of thesynthesizing system of FIG. 4; and

[0027]FIG. 7 is an enlarged perspective view showing a state before thesupporting plate of the synthesizing system of FIG. 6 is connected.

BEST MODE FOR CARRYING OUT THE INVENTION

[0028] Reference will now be made in detail to the preferred embodimentsof the present invention, examples of which are illustrated in theaccompanying drawings. For reference, like reference charactersdesignate corresponding parts throughout several views.

[0029]FIG. 4 illustrates a perspective view showing a state that anupper casing of a LCD projector according to the present invention isremoved, FIG. 5 illustrates an exploded perspective view, partiallyenlarged, FIG. 6 illustrates an enlarged plan view of a supporting platearea of the synthesizing system of FIG. 4, and FIG. 7 illustrates anenlarged perspective view showing a state before the supporting plate ofthe synthesizing system of FIG. 6 is connected.

[0030] For reference, reference numerals designate the same structureand components as the conventional apparatus described in thedescription of the related art section will be omitted.

[0031] As shown in the drawings, an LCD(Liquid Crystal Display)projector includes a lower casing 12 a formed in a rectangle shapehaving a receiving space in the inside by coupling with an upper casing,(not shown), a projection lens 13 placed at a side of the lower casing12 a, a synthesizing system 31 disposed on a side of the projection lens13 along a longitudinal direction of the projection lens 13 inside thelower casing 12 a, an illuminating system casing 22 arranged to surroundthe synthesizing system 31 at a side, dividing beam from a beam sourcein the inside into three color beams of red, green and blue colors andirradiating on LCD panels 33 of the synthesizing system 31, a coolingfan part having a cooling fan (not shown) provided to an adjacentposition (especially, an upper portion) of the synthesizing system 31 tocool the heat generated from the inside of the projector, and asynthesizing system holding plate 71 for preventing distortion and/ormisalignment of the synthesizing system 31 and having both ends fixed onan upper surface of the illuminating system casing 22 and a prescribedarea arranged on an upper surface of the synthesizing system 31 tocontact with the synthesizing system 31.

[0032] Moreover, as shown in FIG. 5, the illuminating system casing 22has a receiving space(S) opened toward the projection lens 13 side tohouse an assembly of the LCD panels 33 and prisms 35. Both ends of thereceiving space(S) are fixed and coupled to a vertical member 45 of aholder body 39. A beam source (not shown) is arranged at a side of theinside of the illuminating system casing 22, and a plurality of opticallenses and optical filters (not shown) are dispersedly arranged todivide beam generated from the beam source into three color beams ofred, green and blue colors.

[0033] Furthermore, the illuminating system casing 22 has a plurality ofboss part 23 projecting to screw a circuit chassis (not shown), and theprojection lens 13 side has a screw hole 25 for passing a fixing screw27 for coupling the synthesizing system holding plate 71 to the fixingscrew 27. Correspondingly, the vertical member 45 of the holder body 39has a screw coupling hole 48 for coupling the fixing screw 27 passingthe screw hole 25.

[0034] Additionally, to hold the upper portion of the synthesizingsystem 31 by compensating the difference in height between theilluminating system casing 22 and the synthesizing system 31, thesynthesizing system holding plate 71 includes a connection part 72having a length corresponding to a width of the receiving space(S) andbent end parts 73 a and 73 b first bent upwardly along a verticaldirection and second bent parallel to the upper surface of theilluminating system casing 22, a projection 74 extending vertically on acentral portion of the connection part 72, and a movement restrictingprojection 76 enlarged from the end of the projection 74 in thedirection of a width of the projection 74. The bent end parts 73 a and73 b have screw holes 75 a and 75 b passing through the surface of theplate respectively.

[0035] Additionally, the prism holder 37 includes a rectangular lowerplate 51 disposed on a lower portion of the prism 35, a rectangularupper plate 49 disposed on an upper portion of the prism 35, ahorizontal part 41 on which the lower plate 51 is seated and connected,and a holder body 39 having the vertical member 45 placed vertically tothe horizontal part 41 and an optical tube of the projection lens passesthrough the central area of the vertical member 45.

[0036] Meanwhile, the upper plate 49 has a pair of movement restrictingparts 78 a and 78 b at the upper surface thereof. The movementrestricting parts 78 a and 78 b touch both sides of the projection 74and elevated to receive the projection 74 along a width direction. Eachmovement restricting part is in the form of a rectangle in case of planeprojection. A side of the projection lens 13 side is contacted with aside of the connection part 72, and the other side of the projectionlens 13 side has a width to contact with an inner surface of themovement restricting projection 76. Especially, it is preferable that acontact line of the movement restricting parts 78 a and 78 b, theprojection 74 and the movement restricting projection 76 is in astraight line for absorbing shock from all directions.

[0037] At a corner part of the upper plate 49 corresponding to themovement restricting parts 78 a an d78 b, formed are height compensatingparts 80 a and 80 b having the same height as the movement restrictingparts 78 a and 78 b in order to maintain the holding panels 71 of theLCD panels 33 in the same height to each other when they are connected.

[0038] Meanwhile, a buffering member 81 is placed between contactsurfaces of the projection 74 and the upper plate 49 as a means forrestricting transfer of the vibration from the illuminating systemcasing 22 contacting with the cooling system casing 63 to the LCD panels33 and the prisms 35 via the projection 74. The buffering member 81includes a side wall part 82 a interposed between the side parts of themovement restricting parts 78 a and 78 b and side parts of theconnection part 72, the projection part 74 and the movement restrictingprojection 76 of the synthesizing holding plate 71, and a lower surfacepart 82 b interposed between the projection 74 and the upper plate 49.

[0039] Referring to the above structure, a connecting process of thepresent invention will be described in brief. The prisms 35 are placedin upright positions along three sides except for the side in which theprojection lens 13 lies, and the upper plate 49 is connected on theupper portion of the prism 35. The lower plate 51 is seated on theholder body 39, and the corresponding LCD panels 33 are coupled to theupper plate 49 and the holder body 39.

[0040] The synthesizing system 31 is placed in the inside the receivingspace of the illuminating system casing 22, and the holder body 39 andthe illuminating system casing 22 are coupled with each other.

[0041] Finally, the buffering member 81 is interposed between the upperplate 49 and the synthesizing system holding plate 71. The fixing screw27 passes the synthesizing system holding plate 71 and the illuminatingsystem casing 22 in order and coupled to the vertical member 45 of theholder body 39.

[0042] Hereinafter, the operation of the projector will be described.The beam irradiated from the beam source contained in the illuminatingsystem casing 22 is divided into three color beams of red, green andblue colors by optical elements having the plurality of optical lensesand the optical filters arranged in the illuminating system casing 22,and the divided beams enter into the corresponding LCD panels 33. Thebeams passing the LCD panels 33 are synthesized through the prisms 35and enlarged and projected on the screen by the projection lens 13.

[0043] When the cooling fan mounted at the adjacent position(especially, the upper portion) of the synthetic system 31 is operatedas the illuminating system 21 operates, the vibration generated as aresult of operation of the cooling fan is transmitted to thesynthesizing system 31 causing the alignment of the prisms 35 and theLCD panels 33 to be distorted from the original position. At this time,the position is supported by the synthesizing system holding plate 71and the vibration of the illuminating system casing 22 isabsorbed/reduced by the buffering member 81, thereby the LCD panels 33and the prisms 35 are stabilized to be maintained at the initialalignment stated and thus the quality of image projected on the screenalso remains at a good condition.

[0044] Meanwhile, in the above embodiment, the buffering member 81 isformed in a single body, but it will be appreciated that the bufferingmember 81 may be divided into a side wall part 82 a and a lower surfacepart 82 b. Alternatively, the buffering member 81 may be coatedintegrally with the surface of the contact surface of the synthesizingsystem holding plate 71.

[0045] The buffering member 81 may be made from sponge, synthetic ornatural rubber and textile.

[0046] Furthermore, if the synthesizing system holding plate 71 is fixedonto the illuminating system casing 22 and forms the contact means withthe upper plate 49, further conditions are not needed, and its detailedcontact shape is not restricted in this embodiment.

[0047] The forgoing embodiments are merely exemplary and are not to beconstrued as limiting the present invention. The present teachings canbe readily applied to other types of devices. The description of thepresent invention is intended to be illustrative, and not to limit thescope of the claims. Many alternatives, modifications, and variationswill be apparent to those skilled in the art.

INDUSTRIAL APPLICABILlTY

[0048] The apparatus to align panels in projector can preventdeviation(misalignment) between at least two or more prisms and panels,which are mounted on the synthesizing system, due to vibration.

What is claimed is:
 1. An apparatus to align panels in projector, the apparatus comprising: a synthesizing system having prisms formed at a rear portion of a projection lens for synthesizing beam, panels mounted parallel to the prisms for forming image and a prism holder having an upper plate located on the upper portion of the prisms for supporting the prisms and the panels; an illuminating system casing having a receiving space opened toward a projection lens side for putting the synthesizing system on the casing and optical paths for irradiating different beams on the panels; and a synthesizing system holding plate for holding the synthesizing system at an upper portion, the synthesizing system holding plate having both ends located on the illuminating system casing and at least one portion located on the upper plate.
 2. The apparatus according to claim 1, wherein the synthesizing system holding plate has bent end parts at both ends thereof to support the synthesizing system even though there is a difference in height between the illuminating system casing and the'synthesizing system.
 3. The apparatus according to claim 1, wherein the synthesizing system holding plate has a projection vertically extending in a direction of the synthesizing system to support the synthesizing system.
 4. The apparatus according to claim 1, further comprising: a projection formed on the synthesizing system holding plate and extending in the direction of the synthesizing system for supporting the synthesizing system; and movement restricting parts elevated from the upper plate for contacting a side surface to an outer circumference of the projection.
 5. The apparatus according to claim 4, wherein the contact part between the projection and the movement restricting parts is a straight line.
 6. The apparatus according to claim 4, wherein the projection has a movement restricting projection extending from an end of the projection to a width direction of the projection and contacting with the movement restricting parts of the upper plate to reliably support the synthesizing system.
 7. The apparatus according to claim 4, wherein the movement restricting parts are in the form of a rectangle.
 8. The apparatus according to claim 1, further comprising a buffering member formed on the contact part between the synthesizing system holding plate and the upper plate for preventing vibration from being transmitted from the illuminating system casing to the synthesizing system.
 9. The apparatus according to claim 8, wherein the buffering member is coated at least on one surface of the contact surface between the synthesizing system holding plate and the upper plate.
 10. The apparatus according to claim 1, further comprising: movement restricting parts elevated at a side of the upper plate, the movement restricting parts contacting a side surface to the synthesizing system holding plate for reliably supporting the synthesizing system; and height compensating parts elevated at the other side of the upper plate in the same height as the movement restricting projections, the height compensating parts being supported by the upper plate and having the same height of panels at two or more portions.
 11. The apparatus according to claim 1, further comprising: a rectangular lower plate disposed on a lower portion of the prism on the prism holder; a horizontal part on which the lower plate is seated and connected; and a vertical member formed at a right angle to the horizontal part, the vertical member being connected to a central area to pass an optical tube of the projection lens.
 12. The apparatus according to claim 1, wherein the panel is an LCD(Liquid Crystal Display) panel.
 13. A structure to align panels in projector, the structure comprising; a projection lens; prisms located on a rear portion o the projection lens for synthesizing beams; panels mounted parallel to the prisms for forming image; a prism holder located on an upper portion of the prisms, the prism holder having an upper plate for supporting the prisms at lower portions of edges thereof, a rectangular lower plate disposed at a lower portion of the prisms, a horizontal part on which the lower plate is seated and connected, and a vertical member standing on the horizontal part and passing an optical path of the projection lens at a central area; an illuminating system casing having a receiving space opened toward a prescribed direction for putting the prism holder thereon and optical paths for irradiating different beams on the panels; a synthesizing system holding plate having a connection part, the connection part having bent end parts vertically bent at both ends to be fixed on the illuminating system casing with a prescribed coupling member and a projection projecting toward the upper plate at a prescribed position of the connection part for supporting the upper plate at an upper portion; and movement restricting parts elevated upwardly from the upper plate, the movement restricting parts contacting a side surface thereof to a side surfaced of the synthesizing system holding plate for supporting the upper plate even to a lateral vibration.
 14. The structure according to claim 13, further comprising height compensating parts elevated in the same height as the movement restricting parts at the other side of the upper plate to make the panels have the same installation height, corresponding to the movement restricting part formed at the side of the upper plate.
 15. The structure according to claim 13, wherein the projection has a movement restricting part at an end, the movement restricting part extending in a width direction of the projection and having a side surface contacting with the movement restricting parts of the upper plate for restricting misalignment of the panels due to external shock.
 16. The structure according to claim 13, wherein a buffering member is inserted in the contact surface between the synthesizing system holding plate and the upper plate for effectively restricting the external vibration.
 17. The structure according to claim 13, further comprising a hole formed in a fixing bond disposed on the upper portion of the panels and a coupling member inserted into the hole of the upper plate, to couple the panels to the upper plate.
 18. A structure to align panels in projector, the structure comprising; a synthesizing system including prisms, LCD panels and a prism holder for synthesizing beams; an illuminating system having optical paths for irradiating different beams on the LCD panels at an adjacent position of the synthesizing system; and synthesizing system holding means having both ends located on the illuminating system casing and at least one area located on the upper plate for supporting the synthesizing system at an upper portion and for restricting misalignment of the LCD panels due to vibration. 